A couple of years ago I wrote about how much we like Gorilla Tape for securing our tubes to the road. Ryan Elliott from URS in Indiana let me know they've found an alternative – Polyken 231 Military Grade Duct Tape. I ordered a case and it looks great, but we haven't been able to use it yet due to the cold/snowy/wet winter (we use nylon straps and nails to secure the middle of the tubes in cold weather).
Polyken 231 appears to be the same quality duct tape as Gorilla Tape at about 2/3 the price (can be even cheaper if you buy big quantities). Check out this link at findtape.com for Polyken 231 Military Grade Duct Tape. Thanks Ryan for the tip!